Why women prefer speed to economy

According to a recent survey by TRL, around 45% of men said they would reduce their speed to save fuel, whereas only 37% of women said the same.

Admittedly, I fall into the 37% category - when I drive my little Matiz on the motorway, I keep to around 68mph as I've found that gives me the best fuel economy. Having said that, I can understand why some women might prefer a little speed every now and again:
a). there's the fact that we take longer to get ready and are therefore more likely to be in a rush
b). women are more likely to have busy social calendars due to an inherent desire to make everyone else happy
c.) there's an argument to say that controlling the speed at which we drive gives us an element of control in an otherwise uncontrollable world
d.) if, as modern working women, we're picking up the fuel bill who is anyone else to argue with us?